Azathioprine for inflammatory bowel disease

This leaflet is for parents and carers about how to use this medicine in children. Our information may differ from that provided by the manufacturers, because their information usually relates to adults. Read this leaflet carefully. Keep it somewhere safe so that you can read it again.

Name of medicine

Azathioprine (ay za THIGH o-prin)

Brand names: Azamune, Imuran

Why is it important for my child to take Azathioprine?

In inflammatory bowel diseases, parts of the colon (large intestine), small intestine, rectum (back passage) and anus become inflamed (red and swollen) and ulcers (sores) may form. This causes symptoms such as diarrhoea, pain, stomach cramps and bleeding from the rectum. In some people, inflammatory bowel diseases are caused by the immune system attacking its own body.

Azathioprine belongs to a group of medicines called immunosuppressants. It works by helping to stop your child’s immune system from attacking their bowel. This reduces the inflammation in the bowels and so reduces the painful symptoms.

What is Azathioprine available as?

  • Tablets: 25 mg, 50 mg
  • Liquid medicine can be ordered specially from your pharmacist

These may contain lactose. If you have any concerns or questions, speak with your child’s doctor or pharmacist.

When should I give Azathioprine

Azathioprine can be given once or twice each day.

  • Once a day: it can be given in the morning or the evening.
  • Twice a day: give once in the morning and once in the evening. Ideally, these times are 10–12 hours apart, for example some time between 7am and 8am, and between 7pm and 8pm.

Give the medicine at about the same time(s) each day so that this becomes part of your child’s daily routine, which will help you to remember.

How much should I give?

Your doctor will work out the amount of Azathioprine (the dose) that is right for your child. The dose will be shown on the medicine label.

It is important that you follow your doctor’s instructions about how much to give.

How should I give Azathioprine?


  • Tablets should be swallowed with a glass of water, squash or juice. Your child should not chew the tablets.
  • You can crush the tablet and mix it with a small amount of soft food such as yogurt, honey, or mashed potato. Make sure your child swallows it straight away, without chewing.
  • Wash your hands and all equipment used thoroughly afterwards to make sure that no-one else takes any of the medicine.

Liquid medicine

  • Shake the medicine well. Measure out the right amount using an oral syringe or a medicine spoon. You can get these from your pharmacist. Do not use a kitchen teaspoon as it will not give the right amount.

Give Azathioprine after your child has eaten and with a glass
of water.

When should the medicine start working?

Azathioprine takes several weeks or even months to start working properly. It may take up to 3 months before you start to see any improvement in your child. It is important that you continue to give Azathioprine during this time.

What if my child is sick (vomits)?

  • If your child is sick less than 30 minutes after having a dose of Azathioprine, give them the same dose again.
  • If your child is sick more than 30 minutes after having a dose of Azathioprine, do not give them another dose. Wait until the next normal dose.

If your child is sick again, seek advice from your family doctor, nurse, pharmacist, or hospital. They will decide what to do based on your child’s condition and the specific medicine involved.

What if I forget to give it?

If you usually give it once a day in the morning: Give the missed dose when you remember during the day, as long as this is at least 12 hours before the next dose is due.

If you usually give it once a day in the evening: If you remember before bedtime, give the missed dose. You do not need to wake a sleeping child to give a missed dose. You can give the missed dose in the morning, as long as this is at least 12 hours before the evening dose is due.

If you usually give it twice a day: If you remember up to 4 hours after you should have given a dose, give your child the missed dose. For example, if you usually give a dose at about 7am, you can give the missed dose at any time up to 11am. If you remember after that time, do not give the missed dose. Give the next dose as usual.

Never give a double dose of Azathioprine.

What if I give too much?

You are unlikely to cause harm if you give an extra dose of Azathioprine by mistake. If you are concerned that you may have given too much, contact your doctor or local NHS services (details at end of leaflet). Have the medicine or packaging with you if you telephone for advice.

Are there any possible side effects?

We use medicines to make our children better, but sometimes they have other effects that we don’t want (side effects).

Side effects you must do something about

If your child gets flu-like symptoms, sore throat, or unusual bleeding or bruising, contact your doctor, as there may be a problem with your child’s blood.

If your child is sick more than once, has stomach pains, is very sleepy or their skin or whites of the eyes have a yellow tinge, contact your doctor or take your child to hospital straight away, as there may be a problem with your child’s liver.

Other side-effects you need to know about

Your child may get some of the following side effects when they first start taking Azathioprine. These usually wear off after a few days as your child gets used to the medicine. If they are still a problem after a week, or you are worried, contact your doctor but continue to give Azathioprine.

  • Your child may feel sick (nausea) and have some diarrhoea. It may help to give Azathioprine with some food or shortly afterwards.

  • Your child may feel less hungry (lose their appetite). Encourage them to eat small meals often.

Can other medicines be given at the same time as Azathioprine?

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Azathioprine should not be taken with some medicines. Tell your doctor or pharmacist about any other medicines your child is taking before giving Azathioprine.

Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal or complementary medicines.

Is there anything else I need to know about this medicine?

If your child comes into contact with anyone who has measles, chickenpox or shingles, contact your doctor straight away, as they may need special preventative treatment.

  • Azathioprine affects your child’s immune system so they may get more infections such as chest infections, coughs and colds and they may take longer to fight these off. Try to keep your child away from people with serious infections if you can, although they can still go to school and nursery as usual.
  • If your child is due to have an immunisation (vaccination), tell the nurse or doctor that they are taking Azathioprine. Some vaccines should not be given.
  • Azathioprine may harm an unborn baby. If your daughter is sexually active, it is important that she uses adequate contraception to prevent pregnancy and continues it for at least 1 month after stopping Azathioprine.
  • If your daughter thinks she may be pregnant, she should see her doctor as soon as possible but continue taking Azathioprine in the meantime.
  • Your child will need regular blood tests to check whether Azathioprine is affecting their blood, kidneys or liver. These tests will need to be done every week for the first month that your child is taking Azathioprine and then at least every 3 months. It is important that you take your child for these blood tests.
  • The oral contraceptive pill can be used safely in women or girls taking Azathioprine.
  • Your child’s skin may become sensitive to sunlight (photosensitivity) and be more likely to get sunburn. They should avoid strong sunlight and should cover their skin, wear a sunhat and use high-factor sunscreen (at least SPF 30) when outside. If your child takes Azathioprine for a long time (several years), there is a theoretical, but unproven, risk that your child may have a slightly higher chance of getting skin cancer if you don’t take these precautions.

General advice about medicines

  • Try to give medicines at about the same times each day, to help you remember.
  • Only give this medicine to your child. Never give it to anyone else, even if their condition appears to be the same, as this could do harm.
  • Make sure that you always have enough medicine. Order a new prescription at least 2 weeks before you will run out.
  • Make sure that the medicines you have at home have not reached the ‘best before’ or ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

If you think someone else may have taken the medicine by accident, contact your doctor straight away.

Where should I keep this medicine?

  • Keep the medicine in a cupboard, away from heat and direct sunlight.
  • It does not need to be kept in the fridge.
  • Make sure that children cannot see or reach the medicine.
  • Keep the medicine in the container it came in.

Who to contact for more information?

Your doctor, pharmacist or nurse will be able to give you more information about Azathioprine and about other medicines used to treat inflammatory bowel disease.

England: NHS 111

Tel 111

Scotland: NHS 24

Northern Ireland: NI Direct

Wales: NHS Direct

Tel 111 (free) or 0845 46 47 (2p per minute)

Crohn's and Colitis UK

Crohn's in Childhood Research Association (CICRA)

020 8949 6209

Copyright disclaimer

Version [2]. © NPPG, RCPCH and WellChild, all rights reserved. Review by April 2018.

The primary source for the information in this leaflet is the British National Formulary for Children. For details on any other sources used for this leaflet, please contact us through our website,

We take great care to make sure that the information in this leaflet is correct and up-to-date. However, medicines can be used in different ways for different patients. It is important that you ask the advice of your doctor or pharmacist if you are not sure about something. This leaflet is about the use of these medicines in the UK, and may not apply to other countries. The Royal College of Paediatrics and Child Health (RCPCH), the Neonatal and Paediatric Pharmacists Group (NPPG), WellChild and the contributors and editors cannot be held responsible for the accuracy of information, omissions of information, or any actions that may be taken as a consequence of reading this leaflet.